As one of the film formation methods of materials for electronic and electric components, there is being widely used a sputtering method capable of easily controlling film thickness and components, ranging from angstrom units to micron orders. This sputtering method employs an apparatus provided with a positive electrode and a negative electrode, in which a substrate and a target are opposed to each other, and a high voltage is applied to between the substrate and the target under an inert gas atmosphere to generate an electric field. The sputtering method uses the following principle. Namely, ionized electrons and inert gas impinge on each other at that time to form plasma, and positive ions in this plasma impinge on a surface of the target (negative electrode) to eject atoms constituting the target. The ejected atoms are deposited on a surface of the opposing substrate to form a film.
The MgO target for sputtering is suitably used when a ground layer of a device having a layered structure, such as a magnetic recording medium, is manufactured (Patent Literature 1).